The present invention relates, in general, to semiconductor devices, and more particularly, to semiconductor devices that utilize silicon carbide.
Previously, the semiconductor industry has employed silicon carbide in the formation of semiconductor diodes and transistors. Due to the greater than 20% lattice structure mismatch between silicon carbide and silicon, prior efforts of growing epitaxial silicon carbide on single crystal silicon generally result in high defect densities, generally greater than 10.sup.6 /cm.sup.2, near the silicon to silicon carbide interface. Such high defect densities restrict the efficiency of semiconductor devices that use such layers. In some cases, a layer of carbon is formed between the silicon and the silicon carbide, often referred to as carbonization, to reduce the defect densities. Such carbonization generally requires temperatures in excess of about 1250 degrees Celsius (.degree. C). Such temperatures can damage the P-N junctions of semiconductor devices.
A further problem is the difficulty in forming thick, greater than approximately 100 nanometers, low defect density, less than 10.sup.6 /cm.sup.2, single crystal silicon on silicon carbide. Therefore, the usefulness of silicon carbide is limited to device structures that do not require single crystal silicon on silicon carbide.
Accordingly, it is desirable to have a method of forming low defect density epitaxial silicon on single crystal silicon carbide, a method of epitaxially applying silicon carbide to single crystal silicon; and to have a transistor structure that utilizes epitaxial silicon carbide on single crystal silicon, and that utilizes epitaxial silicon on single crystal silicon carbide.